<template>
  <div class="nav-bar" :class="{'is_fixed':isFixed}">
    <div class="container">
      <div class="pro-title">
        {{title}}
      </div>
      <div class="pro-param">
        <a href="javascript:;">概述</a><span>|</span>
        <a href="javascript:;">参数</a><span>|</span>
        <a href="javascript:;">用户评价</a>
        <slot name="jing"></slot>
      </div>  
    </div>
  </div>
</template>

<script>
export default {
  name: 'nav-bar',
  props:{
    title: String
  },
  data () {
    return {
      isFixed: false
    }
  },
  mounted() {
    window.addEventListener('scroll',this.initHeight)
  },
  methods: {
    initHeight() {
      let scrollTop = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop
      this.isFixed = scrollTop > 152? true : false
    }
  },
  destroyed() {
    window.removeEventListener('scroll',this.initHeight,false)  //默认true捕获机制 false为冒泡机制
  }
}
</script>

<style lang='scss' scoped>
@import '@/assets/scss/config.scss';
@import '@/assets/scss/mixin.scss';
.nav-bar{
  height: 70px;
  line-height: 70px;
  border-top: 1px solid $colorH;
  background-color: $colorG;
  z-index: 10;
  &.is_fixed{
    position: fixed;
    top: 0;
    width: 100%;
    box-shadow: 0 5px 5px $colorE;
  }
  .container{
    @include flex();
  }
  .pro-title{
    font-size: $fontH;
    color: $colorB;
    font-weight: bold;
  }
  .pro-param{
    font-size: $fontJ;
    span{
      margin: 0 10px;
    }
    a{
      color: $colorC;
    }
  }
}
</style>
